Automatic firearm feed mechanisms



Jan. 18, 1966 R. ZEHNDER AUTOMATIC FIREARM FEED MECHANISMS 3 Sheets-Sheet 1 Filed May 27, 1963 Jan. 18, 1966 R. ZEHNDER 3,229,584

AUTOMATIC FIREARM FEED MECHANISMS Filed May 27, 1963 3 Sheets-Sheet 2 Jan. 18, 1966 R. ZEHNDER AUTOMATIC FIREARM FEED MECHANISMS 3 Sheets-Sheet 5 Filed May 27. 1963 United States Patent Aero-Mecaniques S.A., Geneva, Switzerland, a society of Switzerland Filed May 27, 1963, Ser. No. 283,330 Claims priority, application Luxembourg, May 25, 1962, 41,779 2 Claims. (Cl. 89-33) The present invention relates to feed mechanisms of the rotor type for automatic firearms to which ammunition is fed in the form of an ammunition belt made of cartridges connected by means of links. The invention is more especially, but not exclusively, concerned with feed mechanisms of this type for guns of small caliber, for instance of a caliber ranging from 20 to 50 millimeters.

The term belt feed mechanism of the rotor type designates, in a firearm to which the cartridges are supplied through an ammunition belt (where two successive cartridges are connected together by means of a link comprising clips which resiliently surround said cartridges), a mechanism comprising a rotating structure, called rotor, provided with teeth engaging between the cartridges of the belt and rotated in any suitable manner (for instance under the action of means actuated by powder gases tapped from the gun barrel, or by a movable portion of the gun, or again by a distinct motor) so as to cause the cartridges of the belt to pass successively through an extraction position where they are stripped from the belt links and from which suitable guiding means respectively lead the freed cartridges toward the firearm, through a feed passage, and the belt links stripped from the cartridges toward a link chute.

The term composite link designates the assembly of tWo complementary link elements, each consisting of a simple or multiple (double) clip, assembled together, in tandem-like fashion, either rigidly or with the possibility of limited relative movement, each clip resiliently surrounding a cartridge over at least 180 of its periphery.

Every cartridge of the'ammunition belt is thus caught, over a portion of its length, by one clip of one composite link, and, over at least one other portion of its length, by the other clip of the next link, release of a cartridge from said clips taking place by a relative transverse displacement of said cartridge.

Two successive links of an ammunition belt are thus interconnected by a cartridge which acts as a pin about which said two link elements, or clips, are pivotally connected to each other.

In the following description, the following terms will be used:

The front link element (clip) of a link is that extending in the direction in which the cartridge belt is moving, the other element being the rear link element, or clip.

The middle portion of a link is that through which the front and rear link elements are connected together.

In other words, every cartridge belonging to an ammunition belt is held by the rear clip of a link and the front clip of the next link.

It will be understood that it is possible, with such links, to make two kinds of ammunition belts, to wit:

It is therefore possible to talk, without possibility of misunderstanding, when mentioning an ammunition belt made of links as above described, of one or the other of the two possible kinds of ammunition belts.

According to the present invention, the feed mechanism, which comprises stripping means capable, when an ammunition belt of the first kind is used, of cooperating with the front clip of a link through at least one abutment member capable of holding said clip during the stripping of the cartridge held by it, is characterized by the provision, on the one hand, of means (which may consist of, or belong to, said abutment member) capable, when an ammunition belt of the other kind is used, of forming an abutment for the link the rear clip of which surrounds the cartridge reaching said stripping means and, on the other hand, of supplementary abutment means for preventing any substantial rotation of said rear clip about the axis of the cartridge during the stripping of said cartridge produced by the movement of the rotor.

Preferred embodiments of the present invention will be hereinafter described with reference to the accompanying drawings given merely by way of example and in which:

FIG. 1 is a perspective view of a composite link for making an ammunition belt for use in the belt feed mechanism according to the present invention;

FIG. 2 similarly shows two such links assembled together;

FIGS. 3 and 4 are cross sectional views, respectively before the stripping of a cartridge and during this stripping, of a feed mechanism made according to the invention and fed with a belt of the first kind above mentioned made of link elements as shown by FIGS. 1 and 2;

FIGS. 5 and 6 are views similar to FIGS. 3 and 4 respectively, but wherein the ammunition belt is of the other kind;

FIG. 5a is a detail view showing a detail modification.

In the following description, it will be supposed, as shown by FIG. 1, that every link comprises two portions, one consisting of a single clip 1 and the other consisting of a double clip 2 the respective ends 4a of which are connected together by an arm 4, these two link portions being interconnected through a loop 3 carried by the first portion 1 and engaging the arm 4 of the second portion.

As shown by FIG. 2, the clip 1 of every link is adapted to fit between the two clip portions 2 of the next link and it is provided with two raised side projections 1a adapted to bear on said clip portions 2.

With composite links made as above described, it is possible to form, for a direction of feed of the belt, either of two kinds of ammunition belts, to wit:

The feed mechanism according to the examples shown by the drawings comprises a spindle 5 substantially parallel to the direction of firing of the gun and journalled in a casing, for instance between two transverse walls such as 6 belonging to said casing. Said spindle 5, carrying toothed wheels 7 (the number of which is for instance five) the teeth of which engage between the cartridges 8 of the ammunition belt, thus compels the latter to move forward in the direction indicated by the arrow, from an introduction orifice to a stripping position which will be more explicitly referred to hereinafter. From this stripping position, the cartridges 8, after having been extracted from the clips that held them, are fed by the rotor constituted by said toothed wheels toward a feed passage 9 made into the gun, whereas the stripped. links are led toward an evacuation chute 10.

Advantageously, as shown, there is provided, inside the casing of the feed mechanism, and from the introduction Patented Jan. 18, 1966' .one abutment piece, and preferably two such pieces, con- ;sisting of abutment longitudinally extending members 12,

said members 12 being upported by two levers 13 pivoted about a common axis 14 and being subjected to the action of resilient antagonistic means '(not shown) against the action of which said levers can swing through a limited arc in the direction toward which the links are moving. With such an arrangement, the front end A of the double clip 2 is compelled to bear without sliding against abutment members 12 during the period of stripping of cartridge 8a under the action of toothed wheels 7, as shown by FIG. 4.

It should be noted that, during this stripping period, the whole of the composite link to which belongs the double clip 2 which surrounds cartridge 8a is strongly applied toward the front against members 12 through its front double clip 2 and toward the rear against the next cartridge 8 through the rear single clip 1, said next cartridge 8 being itself maintained by toothed wheels 7 and by guiding surfaces 11.

Now, according to the present invention, the stripping means of the feed mechanism are arranged in such manner that, when use is made of an ammunition belt of the second kind (case of FIGS. 5 and 6), the portion 4a of a composite link the rear double clip 2 of which holds the cartridge 8a which reaches the stripping means bears against an abutment piece located toward the inlet of evacuation chute 10, said abutment piece advantageously consisting, as shown, of the abutments 12 above referred to, and supplementary means are provided to prevent any substantial rotation of said rear double clip 2 about the axis of cartridge 8a while said cartridge is being stripped from the ammunition belt by the wheels 7 of the rotor.

Concerning the above mentioned supplementary abutment means, they may advantageously be made according to one of the two following solutions, both of which may be used together, as shown by FIGS. 5 and 6.

According to a first solution, there is provided, on either side of the inlet region of the stripping means, abutment lugs 15 against which the double rear clip 2 may bear through its rear ends A when the cartridge 8a held by said clip reaches its stripping position (case of FIG. 5).

It should be noted that the rear end A of the rear double clip 2 of a link belonging to an ammunition belt of the second kind happens to be the front end of said clip when said link belongs to a belt of the first kind (case of FIGS. 3 and 4).

If, for constructional reasons, the abutment lugs 15 could not extend sufficiently toward the inside of the stripping meansto form an abutment for said rear end A of the rear double clip 2 during the whole of the stripping step, it would be possible, according to a modification illustrated by FIG. 5a, to mount said lugs pivotally (Within limits) about an axis 16 and to subject them to the action of resilient means, such for instance as a spring 17, tending to bring them back toward the inlet of the stripping means, the abutment lugs 15 accompanying, so to speak, the rear end A of the rear double 'clip 2 during the cartridge stripping period.

According to another solution, the supplementary abutment means intended to prevent the rotation of the double clip 2 about the axis of cartridge 8a consist of a surface 18 carried by, or consisting of, the upper face 10a of evacuation chute 10. Said inclined surface 18 is disposed in such manner as to constitute, during the stripping of cartridge 8a, an abutment for the front single clip 1 of the composite link, the rear double clip of which holds cartridge 8a. Thus, during the stripping of cartridge 8a, the whole of the composite link that is considered is bearing, through its portions 4a, against members 12 and, through the back face of its front single clip, against surface 18, thus preventing, as shown by FIG. 6, any substantial rotation of the double clip 2 about the axis of cartridge 8a and thus permitting said cartridge to be stripped from said clip.

Advantageously, this last described solution is applied in combination with the first one, that is to say with the provision of abutment lugs 15, especially when said lugs are fixed in position. In this case, the composite link, the rear double clip 2 of which holds the cartridge 8a to be stripped, bears First, as FIG. 5, through its portions 4 a, against abutments 12 and, through the rear end A of its rear double clip 2, against abutment lugs 15,

and, as shown by FIG. 6, through its portions 4a, against abutments 12 and through the back surface D of the single front clip 1, against surface 18.

The above description makes clear the operation of the feed mechanism according to the invention.

The possibility for a feed mechanism to work either on the right or on the left with ammunition belts of either of two possible kinds, has, for practical purposes, a considerable advantage.

On the one hand, in military units where there are already stores of both kinds of belts, a feed mechanism according to the invention may use either of these two kinds of belts.

On the other hand, in units supplied with feed mechanisms according to the invention, some of which are fed from the right and others from the left, it will no longer be necessary to provide stores of belts of the two possible kinds since a single kind of belt may be used With either of these two directions of feed, acting as belt of the first kind for the feed mechanisms fed from one side and as belt of the second kind for the feed mechanisms fed from the other side.

In a general manner, While I have, in the above de scription, disclosed what I deem to be practical and efficient embodiments of my invention, it should be well understood that I do not wish to be limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention as comprehended within the scope of the accompanying claims.

What I claim is:

1. In an automatic firearm, a feed mechanism which comprises, in combination, an ammunition belt consisting of a plurality of links and longitudinally extending cartridges each for pivotally connecting two successive links, each of said links comprising two open clips for two successive cartridges, respectively, said clips being offset longitudinally with respect to each other, a casing, an intermittently rotating rotor journalled in said casing about a longitudinal axis and having arms capable of engaging between the cartridges of said belt to propel it laterally, guide means for the cartridges of said belt, extending along cylindrical surfaces coaxial with said rotor, for preventing outward radial movement of said cartridges, a member resiliently movable in said casing away from and toward said rotor adapted to cooperate with the first cartridge of said belt to be pushed by it away from said rotor, first abutment means carried by said member, said abutment means being adapted to cooperate with the tip of one clip of each length to strip said length away from the cartridge on which it is fitted when said belt is disposed with said tip at the front of the corresponding clip, said abutment means being adapted to cooperate with the other end of said last-mentioned clip when said belt is disposed with said tip at the rear of the corresponding clip, second abutment means carried by said casing for preventing any substantial rotation of said last-mentioned clip about the cartridge on which it is mounted during rotation of said rotor when said belt is disposed with said tip at the rear of the corresponding clip, wherein said second abutment means consists of an inclined surface in the top wall of said evacuation chute, said inclined surface being adapted to form, during the evacuation of every link, an abutment for the front clip thereof.

2. In an automatic firearm, a feed mechanism which comprises, in combination, an ammunition belt consisting of a plurality of links and longitudinally extending cartridges each for pivotally connecting two successive links, each of said links comprising two open clips for two successive cartridges, respectively, said clips being offset longitudinally with respect to each other, a casing, an intermittently rotating rotor journalled in said casing about a longitudinal axis and having arms capable of engaging between the cartridges of said belt to propel it laterally, guide means for the cartridges of said belt, extending along cylindrical surfaces coaxial with said rotor, for preventing outward radial movement of said cartridges, a member resiliently movable in said casing away from and towards said rotor adapted to cooperate with the first cartridge of said belt to be pushed by it away from said rotor, first abutment means carried by said member, said abutment means being adapted to cooperate with the tip of one clip of each link to strip said link away from the cartridge on which it is fitted when said belt is disposed with said tip at the front of the corresponding clip, abutment means carried by said casing and adapted to cooperate with the other end of said lastmentioned clip when said belt is disposed with said tip at the rear of the corresponding clip, other abutment means carried by said casing for preventing any substantial rotation of said last-mentioned clip about the cartridge on which it is mounted during rotation of said rotor when said belt is disposed with said tip at the rear of the corresponding clip, said other abutment means consists of abutment lugs adapted to cooperate with said last-mentioned clip through the rear tip thereof when the cartridge cooperating with said last-mentioned clip reaches the position where it is stripped from said belt, said abutment lugs are pivotally mounted, with a possibility of limited pivoting, with respect to said casing, about a longitudinal axis, and means for resiliently opposing pivoting of said lugs.

References Cited by the Examiner UNITED STATES PATENTS BENJAMIN A. BORCHELT, Primary Examiner. 

1. IN AN AUTOMATIC FIREARM, A FEED MECHANISM WHICH COMPRISES, IN COMBINATION, AN AMMUNITION BELT CONSISTING OF A PLURALITY OF LINKS AND LONGITUDINALLY EXTENDING CARTRIDGES EACH FOR PIVOTALLY CONNECTING TWO SUCESSIVE LINKS, EACH OF SAID LINKS COMPRISING TWO OPEN CLIPS FOR TWO SUCCESSIVE CARTRIDGES, RESPECTIVELY, SAID CLIPS BEING OFFSET LONGITUDINALLY WITH RESPECT TO EACH OTHER, A CASING, AN INTERMITTENTLY ROTATING ROTOR JOURNALLED IN SAID CASING ABOUT A LONGITUDINAL AXIS AND HAVING ARMS CAPABLE OF ENGAGING BETWEEN THE CARTRIDGES OF SAID BELT TO PROPEL IT LATERALLY, GUIDE MEANS FOR THE CARTRIDGES OF SAID BELT, EXTENDING ALONG CYLINDRICAL SURFACES COAXIAL WITH SAID ROTOR, FOR PREVENTING OUTWARD RADIAL MOVEMENT OF SAID CARTRIDGES, A MEMBER RESILIENTLY MOVABLE IN SAID CASING AWAY FROM AND TOWARD SAID ROTOR ADAPTED TO COOPERATE WITH THE FIRST CARTRIDGE OF SAID BELT TO BE PUSHED BY IT AWAY FROM SAID ROTOR, FIRST ABUTMENT MEANS CARRIED BY SAID MEMBER, SAID ABUTMENT MEANS BEING ADAPTED TO COOPERATE WITH THE TIP OF ONE CLIP OF EACH LENGTH TO STRIP SAID LENGTH AWAY FROM THE CARTRIDGE ON WHICH IT IS FITTED WHEN SAID BELT IS DISPOSED WITH SAID TIP AT THE FRONT OF THE CORRESPONDING CLIP, SAID ABUTMENT MEANS BEING ADAPTED TO COOPERATE WITH THE OTHER END OF SAID LAST-MENTIONED CLIP WHEN SAID BELT IS DISPOSED WITH SAID TIP AT THE REAR OF THE CORRESPONDING CLIP, SECOND ABUTMENT MEANS CARRIED BY SAID CASING FOR PREVENTING ANY SUBSTANTIAL ROTATION OF SAID LAST-MENTIONED CLIP ABOUT THE CARTRIDGE ON WHICH IT IS MOUNTED DURING ROTATION OF SAID ROTOR WHEN SAID BELT IS DISPOSED WITH SAID TIP AT THE REAR OF THE CORRESPONDING CLIP, WHEREIN SAID SECOND ABUTMENT MEANS CONSISTS OF AN INCLINED SURFACE IN THE TOP WALL OF SAID EVACUATION CHUTE, SAID INCLINED SURFACE BEING ADAPTED TO FORM, DURING THE EVACUATION OF EVERY LINK, AN ABUTMENT FOR THE FRONT CLIP THEREOF. 